(spoilers)The World Ends With You = Sh15uya? D:

[noodle976]

http://en.wikipedia.org/wiki/Sh15uya
"The story centers on a boy named Tsuyoshi trying to recover his memories and find a way out of Shibuya. The inhabitants of Shibuya cannot leave the confines of the city. The world of Shibuya 15 is regulated by an entity know as "Piece" (alternatively translated as "Peace"). Piece locks onto "broken" inhabitants and kills those who have not operated in the proper confines of the world. The victim is "reset" and inserted back into Shibuya with a new name and identity, their previous identity completely wiped from the minds of others."

http://en.wikipedia.org/wiki/The_World_Ends_with_You
"Neku Sakuraba, an antisocial 15 year-old boy, wakes up in what seems to be the Shibuya shopping district of Tokyo, Japan." "Neku is in Shibuya to play the "Reapers' Game" (死神のゲーム, Shinigami no Gēmu?),[1] which spans a total of seven days. Neku is forced to form a pact with a girl named Shiki Misaki in order to avoid being erased from existence.

The Reapers monitor the duo's actions and test them with dangerous and difficult tasks. In order to survive, Neku and Shiki have to defeat the ethereal, animal-like "Noise," physical manifestations of people's negative thoughts and feelings."

Neku Sakuraba=Tsuyoshi, The Reapers or the noise=the "Piece/Peace" D:
Neku can't escape Shibuya, neither can Tsuyoshi D:
Neku and Tsuyoshi both lost their memory :o
Tsuyoshi will be forgotten if he doesn't do whatever the hell he does, and Neku will be erased if he doesn't complete the Reapers' tasks D: